The rise in obesity worldwide parallels a dramatic increase in obesity-associated diseases, most notably type-II diabetes. This disease is predicted to reach epidemic proportions in the next several decades. Thus, understanding the biochemical processes underlying type-II diabetes and identifying new targets for therapeutic intervention are critical for national and world health. Some of the most widely prescribed insulin-sensitizing drugs to treat type-II diabetes belong to the thiazolidinedione (TZD) class of molecules. These drugs were found to also reduce many of the pathologies related to metabolic syndrome including hypertension, abdominal obesity, coronary artery inflammation, multiple sclerosis, Alzheimer's disease and Amyotrophic lateral sclerosis. While the TZDs were originally thought to exert their effects solely through activation of the nuclear transcription factor PPAR?, it is nw known that many of the beneficial effects are mediated in a PPAR?-independent manner. The TZDs were recently shown to interact with a novel mitochondrial protein target called mitoNEET. We reported that the protein mitoNEET is a redox-active, pH-labile 2Fe-2S cluster containing protein in the outer mitochondrial membrane. This is the only known Fe-S protein in the outer mitochondrial membrane. In addition, we discovered that MitoNEET plays an important role in iron management under oxidative stress conditions. Miner1, an endoplasmic reticulum homolog of mitoNEET, is important in maintaining health and longevity and interacts with proteins associated with cancer as well as neurodegenerative diseases. These proteins have emerged as important new therapeutic targets in diseases ranging from diabetes to Alzheimer's. The focus of this proposal is the structural, biochemical and functional characterization of this novel protein family. Specifically, we are investigating the molecular determinants of drug binding as a function of changes in oxidation state and asking how drug binding impacts newly discovered protein-protein interactions that are involved in regulating cell survival and death processes. The proposed studies are of both fundamental significance in understanding this protein-drug recognition as well as the identification of novel therapeutics.